Field of the Invention
The present invention relates to wireless communications, and more particularly, to a method of reselecting a cell by a terminal in a wireless communication system, and an apparatus supporting the method.
Related Art
3GPP (3rd Generation Partnership Project) LTE (long term evolution) which is improvement of UMTS (Universal Mobile Telecommunications System) has been introduced as 3GPP release 8. The 3GPP LTE uses OFDMA (orthogonal frequency division multiple access) in a downlink, and uses SC-FDMA (Single Carrier-frequency division multiple access) in an uplink. The 3GPP LTE adopts MIMO (multiple input multiple output) having maximum four antennas. Recently, a discussion of 3GPP LTE-A (LTE-Advanced) which is the evolution of the 3GPP LTE is in progress.
Due to mobility of a terminal as a mobile device, the quality of a service provided to a current terminal may deteriorate or a cell that may provide a better service can be sensed. Therefore, the terminal may move to a new cell and such an operation is referred to as movement execution of the terminal. The terminal may select a cell on the same frequency, a cell on a different frequency, or a different radio access technology (RAT) cell through cell selection and/or cell reselection and move to the corresponding cell.
Meanwhile, although operators who provide wireless communication services can independently implement a communication system for providing the services, it is also possible to share systems implemented by specific operators. According to such a communication system environment, there may be a situation where a specific cell is shared by a plurality of operators.
When one cell is shared by the plurality of operators, a UE performs a cell reselection procedure by commonly applying information for the cell reselection. Therefore, a cell capable of providing an optimal service to the UE may not be selected as a target cell. As a result, a problem may occur in which quality of a service provided to the UE deteriorates. Accordingly, there is a need for a cell reselection method in which the UE can select a proper target cell through the cell reselection in an environment where the communication system can be fully or partially shared by the plurality of operators.